1. Field of the Invention
The present invention relates to an elastomer composition and a rubber roller composed of the elastomer composition. More particularly, the present invention relates to the elastomeric composition that can be preferably used as a rubber roller in a paper-feeding mechanism of an ink jet printer, a laser printer, an electrostatic copying apparatus, a facsimile apparatus, an automatic deposit payment machine (ATM), and the like, to feed objects such as sheets of paper or films by picking up the objects one by one, separately, from the objects piled up one upon the other. Therefore, the present invention is intended to provide the rubber roller with a high friction coefficient and a high wear resistance.
2. Description of the Related Art
A paper-feeding roller formed by molding a rubber composition is used in the paper-feeding mechanism of electrostatic copying apparatus, laser printers, ink jet printers, facsimile apparatus; and automatic deposit payment machines (ATM). Paper-feeding rollers composed of rubber compositions have the problem that the paper supply state becomes bad due to the blooming of sulfur contained in the rubber composition.
A vulcanizing system consisting of a peroxide is known as a rubber-vulcanizing system which does not use sulfur. To suppress blooming, a paper-feeding roller using rubber vulcanized by a vulcanizing system consisting of an organic peroxide is proposed.
Disclosed in Japanese Patent Application Laid-Open No. 8-334939 is a rubber composition for a roller containing 100 parts by weight of ethylene-propylene copolymer and 3 to 6 parts by weight of vulcanizing agent containing a peroxide.
Disclosed in Japanese Patent Application Laid-Open No. 2000-248133 is a rubber composition containing ethylene-propylene-diene rubber, carbon black (not less than 25 wt % nor more than 50 wt %) in which an oil absorption amount is specified, paraffin process oil, and an organic peroxide for crosslinking the ethylene-propylene-diene rubber.
However, although blooming does not occur in the paper-feeding roller using rubber vulcanized by the vulcanizing system consisting of organic peroxide, the wear resistance of the paper-feeding roller is inferior to that of a paper-feeding roller using rubber vulcanized with sulfur.
The paper-feeding roller proposed in Japanese Patent Application Laid-Open No. 8-334939 is capable of favorably feeding not more than 200,000 sheets of paper. That is, the paper-feeding roller has a problem in its wear resistance.
The paper-feeding roller proposed in Japanese Patent Application Laid-Open No. 2000-248133 contains a large amount of carbon black to secure electric conductivity. More specifically, the paper-feeding roller contains not less than 25 wt % nor more than 50 wt % of the carbon black. The paper-feeding roller has favorable electric conductivity, but has a problem in its wear resistance because the paper-feeding roller becomes worn due to repeated contact between it and paper. Another problem of the paper-feeding roller is that the paper is stained with the carbon black. The paper-feeding roller has still another problem in that it has a high hardness due to the reinforcing effect of the carbon black and hence does not have a sufficient friction coefficient.